spreadsheet setup help

Hello,

I am trying to set up a spreadsheet that has all of our project lists and tasks on it. I have it set up so far that I can sort using the filter feature. I have it set up for priority of the project (high, med, low), ,who is responsible for completeing the project, the project name. and then i'm stuck at the tasks. I want to be able to search by priority responsibility or project but the problem i run into is that I have multiple tasks for each project and when I sort it doesn't sort right. does anyone have an example how to sort when there are multiple cells. I have probally confused everyone so far. thanks for any help